1. Field of the Invention
Aspects of the invention relate to power conversion device control devices that drive semiconductor elements.
2. Related Art
As this kind of power conversion device control device, there is known, for example, a power transistor module failure determination method of individually determining failure causes by giving pulse widths of failure detection signals differing setting times in accordance with an overheat failure, an overcurrent failure, a short circuit failure, and an insufficient voltage failure detected in a power transistor module that drives an inverter. See, for example, Japanese patent publication no. JP-A-08-70580 (also referred to herein as “PTL 1”).
Also, as another power conversion device control device, there is known a power module wherein, when decoding signals output by four protection circuits in a decoder and outputting a result thereof from three output terminals, decoding is carried out in such a way that a combination of the values of one or more detection signals is correlated to plural combinations of the protection circuit output signals in the decoder. See, for example, Japanese patent publication no. JP-A-10-267977 (also referred to herein as “PTL 2”).
Furthermore, as another power conversion device control device, there is proposed an intelligent power module that includes a required number of semiconductor switching elements, a drive circuit, various kinds of detector circuit and warning circuit that detect a fatal error and precursory error of the switching elements, drive circuit, or the like, an error detector logic circuit that carries out a protection operation for the switching elements when an error is detected by the detector circuits and warning circuits, a control circuit for outputting a signal based on an error detection signal to the exterior, and a transmission circuit. See, for example, Japanese patent publication no. JP-A-2002-27665 (also referred to herein as “PTL 3”).
In the heretofore known example described in PTL 3, an output terminal that outputs an alarm signal when a fatal error is detected, and an output terminal that outputs an error cause determination signal indicating causes of errors including fatal errors and precursory errors, are provided in the transmission circuit, and these are preferably used together as a single output terminal.
However, in the heretofore known example described in PTL 1, an overheat failure, overcurrent failure, short circuit failure, and insufficient voltage failure of the power transistor module are detected individually, pulse signals of differing pulse widths are supplied to an OR gate, and a collective failure detection signal is output from the OR gate. Because of this, even though an overheat failure, overcurrent failure, short circuit failure, and insufficient voltage failure are detected individually, and pulse signals of differing pulse widths are output, each pulse signal is passed through the OR gate and formed into a collective failure detection signal, meaning that when another error occurs in a condition in which plural errors are occurring simultaneously, or one error is occurring, there is an unsolved problem in that the pulse width of the error detection signal increases in length, and it is not possible to carry out a normal error detection.
Also, in the heretofore known example described in PTL 2, when decoding signals output by four protection circuits in the decoder and outputting a result thereof from three output terminals, a combination of the values of one or more detection signals is correlated to plural combinations of the protection circuit output signals in the decoder, and a protection operation condition is notified of with the number of output terminals less than the number of protection circuits. Because of this, it is possible to solve the unsolved problem of PTL 1, but there is an unsolved problem in that it is necessary to form plural output terminals, and the manufacturing cost soars.
Furthermore, in the heretofore known example described in PTL 3, when alarm signals or warning signals output from the various kinds of detector circuit and warning circuit that detect a fatal error and precursory error of the switching elements, drive circuit, or the like, are input into the control circuit, the signals are latched, the protection circuit operation to be carried out next is not accepted until the signal latch is released, and it is possible to prevent an erroneous detection. However, with PTL 3, when configuring, for example, a three-phase inverter with six identical driver ICs, there is an unsolved problem in that a transmission circuit that collects and processes signals from each driver IC is needed, and the manufacturing cost soars.